One of the reasons for a traffic drop can also be due to your site losing links. You may be seeing a direct loss of that referral traffic, but there could also be indirect effects. When your site loses inbound links, it tells Google that your site isn't as authoritative anymore, which leads to lower search rankings that in turn lead to traffic drops (because fewer people are finding your site if it's not ranked as highly and more).
I love your post. I keep coming back because you always have great content I can use in my business as well as share. Since I own my own Digital Marketing company I guess you would be one of THE influencers in Internet Marketing field. I just started my business and because most influencers on twitter are talking about Content Marketing, that is what I have been writing about. But my site is only about a month old so I will just stay consistent in my writing. I’m also in the process of changing my navigation bar so be know how to get to what they want faster. Which would be “what is SEO”, etc. Thanks and would love any advice you can give me.